Bifunctional chair for sitting and kneeling

ABSTRACT

The subject matter of the invention is a convertible bi-functional chair for sitting and kneeling, which allows to change positions and relieve the spine during long-lasting work involving sitting or long travels by plane, bus or train. 
     The bi-functional chair for sitting and kneeling comprises a movable rotating seat ( 1 ), back rest ( 3 ) and knee support ( 6 ). It is equipped with devices allowing to change the distance between the front edge of the seat and the back rest, the angle of inclination of the back rest with regard to the seat and the height of the back rest with regard to the seat, which enables converting the seat and back rest for classic sitting into a seat and back rest for kneeling and vice versa.

The subject matter of the invention is a convertible bi-functional chairfor sitting and kneeling, which allows to change positions and relievethe spine during long-lasting work involving sitting or long travels byplane, bus or train.

A chair for kneeling is known from the Polish utility model no. 64081.It is a rehabilitation chair used mainly for kneeling, without abackrest, constructed in the shape of the letter X.

Another solution with a similar purpose is known from the Polish patentapplication P.390736. It is a convertible piece of furniture for sittingand kneeling in which a two-part kneeler assembly is supported onrotational and tilting arms mounted in brackets in a crosspiece.

Other solutions with similar uses are known, such as the solution fromEuropean patent description no. EP 0570550, in which the seat, kneesupport and backrest are suspended on a suitable mechanism from thesupporting column based on a wheeled mount. This mechanism compriseslevers allowing for moving the usable surfaces of the chair in space,depending on the needs. In this way the chair may be converted to asitting position, sitting-kneeling position or similar. Locking theposition of the seat, kneeler and backrest is effected by means of latchand bolt mechanisms.

Pieces of furniture of a similar type are also known from the Polishpatent application no. P.387898. The chair described therein is equippedwith a seat, two-part knee support, backrest and armrests. The kneelerassembly contains two parts. Each of these parts is able to tilt thekneeling chair and move it backwards.

A solution is also known from patent application PCT/IB2014/000114 theessential feature of which consists in the fact that the seat of thechair is dividable. Its front part converts into a kneeler. The chairpossesses a two-arm seat support. Its movable arm supports the frontpart of the seat convertible into a kneeler and the second arm supportsthe back part of the seat and the backrest.

A solution in the form of a multi-purpose chair for yoga practice inwhich the kneeler is lowered along the seat column is known from theU.S. Pat. No. 794,672 B2.

Precise adjustment of the bi-functional chair for the function ofsitting and kneeling, aside from changing the angle of inclination ofthe seat, requires changing the depth of the seat, the angle of thebackrest in relation to the seat as well as adjustment of the height ofthe backrest in relation to the seat.

In kneeling form the depth of the seat is lower than during classicsitting. Depending on the manner of mounting and arrangement of thekneeler, in variants with dividable and non-dividable seat, the depth ofthe seat should be decreased or increased.

On account of changing the angle of inclination of the seat duringconversion of the chair it is necessary to change the angle of thebackrest in relation to the seat.

In order to appropriately support the lumbar section of the spine thebackrest should be profiled and convex in the lumbar section. In orderto ensure the appropriate placement of the backrest in both positions ofthe chair the backrest is preferably adjustable in height with regard tothe seat.

Bi-functional chairs known from prior art do not offer the possibilityto precisely adjust the device to the function of sitting and kneeling,at the same time preserving the aforementioned conditions.

The bi-functional chair for sitting and kneeling according to theinvention contains a seat with adjustable angle of inclination, backrestand movable knee support. It is equipped with a device or severaldevices allowing to change the distance between the front edge of theseat and the backrest, the angle of inclination of the backrest inrelation to the seat and the height of the backrest in relation to theseat, which enables precise conversion of the seat and backrest forclassic sitting into a seat and backrest for kneeling and vice versa.

It is beneficial if the change of depth of the seat is ensured by aslide device in which the seat, being manually movable in relation tothe backrest, is connected by means of the slide mechanism to the seatmount and the seat plate is rotationally connected to the chair pedestalassembly. Manual change of the angle between the backrest and the seatis enabled by the rotational connection of the frame of the backrest tothe rear part of the seat plate. Manual change of the height of thebackrest in relation to the seat is enabled by the connection of thebackrest to the backrest support which is movable in the verticaldirection.

If is beneficial if the chair for sitting and kneeling is equipped witha device maintaining the backrest angle selected by the user without thenecessity to lock the movement of the backrest. Such a device does notrequire additional locking activities and allows the user to quickly andfluidly change the angle of inclination of the backrest by pushing withthe back.

If is beneficial if the chair for sitting and kneeling is equipped witha device maintaining the backrest angle selected by the user without thenecessity to lock the movement of the backrest, which possesses anassembly for equalizing the resistance of the backrest with the weightof the user. This device does not require regulating the chair for eachuser.

It is beneficial if the change of depth of the seat and the change ofthe angle between the backrest and the seat is ensured by a device inwhich the backrest support is connected by means of a shift and rotationmechanism with the seat plate connected rotationally to the chairpedestal assembly. It ensures manual adjustment of the angle between thebackrest and the seat and the possibility to manually shorten or extendthe backrest. Manual change of the height of the backrest in relation tothe seat is enabled by the connection of the backrest to the backrestsupport which is manually movable in the vertical direction.

It is beneficial if the change of the depth of the seat and the heightof the backrest in relation to the seat is enabled by a device in whichthe support of the seat is connected rotationally to the mount of theseat, the rear part of the seat is extended by at least 35 mm and thebackrest support is shaped in such a manner, that in the sittingposition the lumbar support point of the backrest located closest to thefront overlaps at least 35 mm on the seat. Owing to the above, afterarranging the chair in the kneeling position the rear part of the seatis automatically extended. Adequate setting of the height of thebackrest is ensured by placement of the axis of the backrest support atthe end of the seat plate. The height of the backrest changesautomatically. Manual change of the angle between the backrest and theseat is enabled by the rotational connection of the frame of thebackrest to the rear part of the seat plate.

It is beneficial if the change of the depth of the seat, the angle andthe height of the backrest in relation to the seat is enabled by adevice in which the support of the seat is connected rotationally to themount of the seat, the rear part of the seat is extended by at least 35mm and the backrest support is shaped in such a manner, that in thesitting position the lumbar support point of the backrest locatedclosest to the front overlaps at least 35 mm on the seat. The backrestsupport is connected by means of sliders through the sliding componentto the seat support, which ensures automatic correction of the anglebetween the seat and the backrest during conversion of the chair. Theseat extends automatically. Adequate setting of the height of thebackrest is ensured by placement of the axis of the backrest support atthe end of the seat plate. The height of the backrest changesautomatically.

It is beneficial if the change of the depth of the seat, the angle andheight of the backrest in relation to the seat is enabled by a device inwhich the support of the seat is connected rotationally to the supportof the seat, the rear part of the seat is extended by at least 35 mm andthe backrest support is shaped in such a manner, that in the sittingposition the lumbar support point of the backrest located closest to thefront overlaps at least 35 mm on the seat. The rear part of the seatplate is rotationally connected to a string which on its other end isconnected rotationally to the mounting plate of the backrest support.The front of the mounting plate of the backrest support is rotationallyconnected to a string which on its other end is rotationally connectedto the seat support. This string is additionally rotationally connectedto a string which on its other end is connected with the lower plate ofthe seat. The device enables automatic extension of the seat, automaticcorrection of the backrest angle, automatic correction of the height anddistance of the backrest from the seat after arranging the chair in thekneeling position. The mounting plate of the backrest is affixed to theseat support by means of a rotational connection. It provides anadditional function—a manually changeable angle between the backrest andthe seat which aims at inclining the backrest in both positions of thechair.

It is beneficial if the change of the depth of the seat, the angle andheight of the backrest in relation to the seat is enabled by a device inwhich the support of the seat is connected rotationally with the chairpedestal assembly, the rear part of the seat is extended by at least 35mm and the backrest support is shaped in such a manner, that in thesitting position the lumbar support point of the backrest locatedclosest to the front overlaps at least 35 mm on the seat. The rear partof the lower plate of the seat is rotationally connected to a stringwhich on its other end is rotationally connected to the slidingcomponent. This sliding component is connected to the chair pedestalassembly by means of any sliding mechanism allowing for vertical up-downmovement. The device enables automatic extension of the seat, automaticcorrection of the backrest angle, automatic correction of the height anddistance of the backrest from the seat after arranging the chair in thekneeling position. The sliding component is rotationally affixed withthe chair seat support which is in turn rotationally affixed to thebackrest support. This provides an additional function—a manuallychangeable angle between the backrest and the seat which aims atinclining the backrest in both positions of the chair.

It is beneficial if the change of the depth of the seat, the angle andheight of the backrest in relation to the seat is enabled by a device inwhich the support of the seat is connected rotationally to the chairpedestal assembly, the rear part of the seat is extended by at least 35mm and the backrest support is shaped in such a manner, that in thesitting position the lumbar support point of the backrest locatedclosest to the front overlaps at least 35 mm on the seat. The rear partof the lower seat plate is rotationally connected to a string which onits other end is connected rotationally to the mounting plate of thebackrest support. The plate is rotationally connected to strings whichon their other sides are rotationally connected to the seat supportassembly. The axes of rotation of the strings are situated in relationto each other in the form of a rhomboid. The plate is rotationallyconnected to the backrest support which in turn is affixed to thebackrest by means of a rotational connection. The device enablesautomatic extension of the seat, automatic correction of the backrestangle, automatic correction of the height and distance of the backrestfrom the seat after arranging the chair in the kneeling position. Therotational connection provides an additional function, namely manuallychangeable angle between the backrest and the seat which aims to inclinethe backrest in both positions of the chair.

It is beneficial if the change of the depth of the seat, the angle andheight of the backrest in relation to the seat is enabled by a device inwhich the support of the seat is connected rotationally to the chairpedestal assembly, the rear part of the seat is extended by at least 35mm and the backrest support is shaped in such a manner, that in thesitting position the lumbar support point of the backrest locatedclosest to the front overlaps at least 35 mm on the seat. The rear partof the seat plate is rotationally connected to a string (which on itsother end is rotationally connected to the mounting plate of thebackrest support). The front of the mounting plate of the backrestsupport is rotationally connected to a string which on its other end isrotationally connected to the chair pedestal assembly. This string isadditionally rotationally connected to the string which on its other endis connected with the lower plate of the seat. The device enablesautomatic extension of the seat, automatic correction of the backrestangle, automatic correction of the height and distance of the backrestfrom the seat after arranging the chair in the kneeling position. Themounting plate of the backrest is rotationally connected to the backrestsupport. It provides an additional function—a manually changeable anglebetween the backrest and the seat. Another additional function isprovided by the inclination mechanism. In the sitting position themechanism enables the inclination of the seat by means of moving thebackrest backwards which, by affecting the seat mount/chair pedestalelement, increases the angle between the seat and the backrest, which isbeneficial for the spine.

A beneficial result of the invention is a better support for the back ofthe user which is possible owing to the fact that part of the backrestsupporting the lumbar section of the spine is set on an appropriateheight. What is more, the depth of the seat is decreased when the chairis arranged in the kneeling position and the angle of the backrest isadjusted for both positions of the chair. What is also beneficial is theintroduction of the possibility to incline the backrest backwards inboth positions of the chair, so as to place it in a more or lessvertical position. Another beneficial fact is the introduction of amechanism which, in the sitting position, when the backrest is movedbackwards, also causes the inclination of the seat by around 50% of theangle of inclination of the backrest, which increases the angle betweenthe seat and the backrest.

A beneficial result of the invention resides in the fact that it ispossible to market new variants of the bi-functional chair with betterfunctionalities and introduce this form of seating in buses, trains andplanes, which would facilitate travelling for people suffering from backaches.

Embodiments of the subject matter of the invention are presented on thefollowing drawing, where:

FIG. 1 presents the bi-functional chair with a person sitting in theclassic position, with a device allowing for changing the distancebetween the front edge of the seat and the backrest, the angle ofinclination of the backrest in relation to the seat and the height ofthe backrest in relation to the seat.

FIG. 2 presents the bi-functional chair with a person sitting in theclassic position, with a device allowing for changing the distancebetween the front edge of the seat and the backrest, the angle ofinclination of the backrest in relation to the seat and the height ofthe backrest in relation to the seat.

FIG. 3 presents the bi-functional chair arranged in the classicposition, with sliding seat allowing for manual change of the distancebetween the front edge of the seat and the backrest, with manual changeof the angle of inclination of the backrest in relation to the seat andmanual change of the height of the backrest in relation to the seat.

FIG. 4 presents the bi-functional chair arranged in the kneelingposition, with sliding seat allowing for manual change of the distancebetween the front edge of the seat and the backrest, with manual changeof the angle of inclination of the backrest in relation to the seat andmanual change of the height of the backrest in relation to the seat.

FIG. 5 presents the bi-functional chair arranged in the classicposition, with sliding backrest allowing for manual change of thedistance between the front edge of the seat and the backrest, withmanual change of the angle of inclination of the backrest in relation tothe seat and manual change of the height of the backrest in relation tothe seat.

FIG. 6 presents the bi-functional chair arranged in the kneelingposition, with sliding backrest allowing for manual change of thedistance between the front edge of the seat and the backrest, withmanual change of the angle of inclination of the backrest in relation tothe seat and manual change of the height of the backrest in relation tothe seat.

FIG. 7 presents the bi-functional chair arranged in the classic positionin which the rear part of the seat is extended by at least 35 mm and thebackrest support is shaped in such a manner, that in the sittingposition the lumbar support point of the backrest located closest to thefront overlaps at least 35 mm on the seat. This chair is equipped with amanual mechanism for setting the angle of the backrest support and asupport axis located at the end of the seat plate.

FIG. 8 presents the bi-functional chair arranged in the kneelingposition in which the rear part of the seat is extended by at least 35mm and the backrest support is shaped in such a manner, that in thesitting position the lumbar support point of the backrest locatedclosest to the front overlaps at least 35 mm on the seat. This chair isequipped with a manual mechanism for setting the angle of the backrestsupport and a support axis located at the end of the seat plate.

FIG. 9 presents the bi-functional chair arranged in the classicposition, with a mechanism automatically adjusting the angle between thebackrest and the seat during conversion of the chair from the sittingposition to the kneeling position. This chair is equipped with a supportaxis located at the end of the seat plate.

FIG. 10 presents the bi-functional chair arranged in the kneelingposition, with a mechanism automatically adjusting the angle between thebackrest and the seat during conversion of the chair from the sittingposition to the kneeling position. This chair is equipped with a supportaxis located at the end of the seat plate.

FIG. 11 presents the bi-functional chair arranged in the classicposition, with a backrest setting device in which the backrest mountingplate is movable by means of sliders. The chair possesses an additionalfunction of inclining the backrest backwards.

FIG. 12 presents the bi-functional chair arranged in the kneelingposition, with a backrest setting device in which the backrest mountingplate is movable by means of sliders. The chair possesses an additionalfunction of inclining the backrest backwards.

FIG. 13 presents the bi-functional chair arranged in the classicposition, with a backrest setting device in which the backrest mountingplate is movable by means of a sliding mechanism. The chair possesses anadditional function of inclining the backrest backwards.

FIG. 14 presents the bi-functional chair arranged in the kneelingposition, with a backrest setting device in which the backrest mountingplate is movable by means of a sliding mechanism. The chair possesses anadditional function of inclining the backrest backwards.

FIG. 15 presents the bi-functional chair arranged in the classicposition, with a backrest setting device in which the backrest mountingplate is movable by means of strings arranged in relation to each otherin the form of a rhomboid. The chair possesses an additional function ofinclining the backrest backwards.

FIG. 16 presents the bi-functional chair arranged in the kneelingposition, with a backrest setting device in which the backrest mountingplate is movable by means of strings arranged in relation to each otherin the form of a rhomboid. The chair possesses an additional function ofinclining the backrest backwards.

FIG. 17 presents the bi-functional chair arranged in the classicposition, with a backrest setting device in which the backrest mountingplate is movable by means of sliders. The chair possesses an additionalfunction of inclining the backrest backwards synchronized with thefunction of inclining the seat. The backrest of the chair on this figureis set in the vertical position.

FIG. 18 presents the bi-functional chair arranged in the classicposition, with a backrest setting device in which the backrest mountingplate is movable by means of sliders. The chair possesses an additionalfunction of inclining the backrest backwards synchronized with thefunction of inclining the seat. The backrest of the chair on this figureis set in the maximally reclined position.

FIG. 19-20 present an embodiment of the bi-functional chair with adevice for moving the seat and setting the backrest in the classicsitting position and the kneeling position mounted on a stationarypedestal in means of transportation.

FIG. 21 presents the bi-functional chair with a device maintaining thebackrest angle selected by the user without the necessity to lock themovement of the backrest manually.

FIG. 22 presents the device maintaining the backrest angle selected bythe user without the necessity to lock the movement of the backrestmanually.

FIG. 23 presents the device maintaining the backrest angle selected bythe user without the necessity to lock the movement of the backrestmanually, which contains an assembly for equalizing the resistance ofthe backrest with the weight of the user.

The embodiment presented on FIGS. 1 and 2 shows a person sitting in theclassic position and in the kneeling position, respectively, on abi-functional chair for sitting and kneeling equipped with a deviceautomatically changing the distance between the front edge of the seatand the backrest, the angle of inclination of the backrest in relationto the seat and the height of the backrest in relation to the seat. Thedevice converts the seat and the backrest for classic sitting into aseat and backrest for kneeling and vice versa.

The embodiment presented on FIGS. 3 and 4 shows the bi-functional chairfor sitting and kneeling equipped with a seat with a changeable angle ofinclination, backrest and movable knee support in two positions. Allregulations are manual. The seat of chair 1 is connected by means of anytype of sliding mechanism 7 to seat mount 2. Movement of mechanism 7 maybe locked or unlocked by any means—an example slide lock 11. Seat mount2 is rotationally connected (rotation axis 8) to seat support 4.Rotation may be locked or unlocked by any means—an example rotation lock9. Seat mount 2 is rotationally connected (rotation axis 10) to backrestsupport 5. Rotation may be locked or unlocked by any means. Backrestsupport 5 is affixed with any type of vertical sliding mechanism 14 tobackrest 3. Movement of the backrest may be locked or unlocked by anymeans—an example slide lock 13. If the seat is dividable the kneesupport 6 constitutes an extension of the seat when the chair isarranged in the sitting position; if the seat is not dividable the kneesupport 6 is placed under the seat and is moved to the kneeling positionduring conversion of the chair by means of any mechanism.

The embodiment presented on FIGS. 5 and 6 shows the bi-functional chairfor sitting and kneeling equipped with a seat with a changeable angle ofinclination, backrest and movable knee support in two positions. Allregulations are manual. Seat mount 2 is rotationally connected (rotationaxis 8) to seat support 4. Rotation may be locked or unlocked by anymeans—an example rotation lock 9. Seat mount 2 is connected by means ofa rotational-sliding mechanism or rotational (rotation axis 16) andsliding mechanism 15 to backrest support 5. Movement may be locked byany means—example slide and rotation lock 17. Backrest support 5 isconnected with a vertical sliding mechanism 14 to backrest 3. Movementmay be locked by any means—example slide lock 13. If the seat isdividable the knee support 6 constitutes an extension of the seat whenthe chair is arranged in the sitting position; if the seat is notdividable the knee support 6 is placed under the seat and is moved tothe kneeling position during conversion of the chair by means of anymechanism.

The embodiment presented on FIGS. 7 and 8 shows the bi-functional chairfor sitting and kneeling equipped with a seat with a changeable angle ofinclination, backrest and movable knee support in two positions.Regulation of the backrest angle is manual, setting the seat depth andheight of the backrest over the seat is an automatic process effectedduring conversion of the chair from the classic sitting position intothe kneeling position. Seat mount 2 is rotationally connected (rotationaxis 8) to seat support 4. The movement of this connection may be lockedby any means—an example rotation lock 9. Backrest support 5 isrotationally connected (rotation axis 18) to the end of seat mount 2.The movement of this connection may be locked by any means—an examplerotation lock 19. Backrest support 5 is shaped in such a manner that inthe sitting position the lumbar support point of the backrest locatedclosest to the front overlaps at least 35 mm on the seat. Backrestsupport 5 is affixed to backrest 3. If the seat is dividable the kneesupport 6 constitutes an extension of the seat when the chair isarranged in the sitting position; if the seat is not dividable the kneesupport 6 is placed under the seat and is moved to the kneeling positionduring conversion of the chair by means of any mechanism.

The embodiment presented on FIGS. 9 and 10 shows the bi-functional chairfor sitting and kneeling equipped with a seat with a changeable angle ofinclination, backrest and movable knee support in two positions. Settingof the backrest angle, seat depth and height of the backrest over theseat is an automatic process effected during conversion of the chairfrom the classic sitting position into the kneeling position and viceversa. Seat mount 2 is rotationally connected (rotation axis 8) to seatsupport 4. Rotation of this connection may be locked by any means—anexample rotation lock 9. Backrest support 5 is rotationally connected(rotation axis 18) to the end of seat mount 2. Backrest support 5 isshaped in such a manner that in the sitting position the lumbar supportpoint of the backrest located closest to the front overlaps at least 35mm on the seat. Backrest support 5 is affixed to backrest 3. Thebi-functional is equipped with a mechanism automatically adjusting theangle between the backrest and the seat during conversion of the chairfrom the sitting position to the kneeling position constructed in such amanner that seat support 4 is rotationally connected (connectionrotation axis 22) to string 21 which on its other end is connectedrotationally (connection rotation axis 23) with sliding component 24.Element 24 is connected to seat mount 2 by means of a horizontal slidingmechanism allowing for movement from the end to the front (and viceversa) of the seat. Sliding element 24 is rotationally connected(connection rotation axis 23) t string 25 which on its other end isconnected rotationally (connection rotation axis 26) to the short arm ofbackrest support 27—connection rotation axis 18. If the seat isdividable the knee support 6 constitutes an extension of the seat whenthe chair is arranged in the sitting position; if the seat is notdividable the knee support 6 is placed under the seat and is moved tothe kneeling position during conversion of the chair by means of anymechanism.

The embodiment presented on FIGS. 11 and 12 shows the bi-functionalchair for sitting and kneeling equipped with a seat with a changeableangle of inclination, backrest and movable knee support in twopositions. Setting of the backrest angle, seat depth and height of thebackrest over the seat is an automatic process effected duringconversion of the chair from the classic sitting position into thekneeling position and vice versa. Seat mount 2 is rotationally connected(rotation axis 8) to seat support 4. Rotation of this connection may belocked by any means—an example rotation lock 9. String 29 isrotationally connected (connection rotation axis 28) to the rear part ofseat mount 2. The other side of the string is rotationally connected(connection rotation axis 30) to backrest support mounting plate 31. Thefront of the backrest support mounting plate 31 is rotationallyconnected (connection rotation axis 32) to string (33) which on itsother end is rotationally connected (connection rotation axis 34) to thechair pedestal assembly 4. In addition, string 33 is rotationallyconnected (rotation axis 35) to string 36 which on its other end isrotationally connected (connection rotation axis 37) to seat mount 2.Backrest support 20 is rotationally connected (rotation axis 38) to thebackrest support mounting plate 31. Rotation of this connection may belocked by any means—an example rotation lock 39. Backrest 3 is affixedto backrest support 31. If the seat is dividable the knee support 6constitutes an extension of the seat when the chair is arranged in thesitting position; if the seat is not dividable the knee support 6 isplaced under the seat and is moved to the kneeling position duringconversion of the chair by means of any mechanism.

The embodiment presented on FIGS. 13 and 14 shows the bi-functionalchair for sitting and kneeling equipped with a seat with a changeableangle of inclination, backrest and movable knee support in twopositions. Setting of the backrest angle, seat depth and height of thebackrest over the seat is an automatic process effected duringconversion of the chair from the classic sitting position into thekneeling position and vice versa. Seat mount 2 is rotationally connected(rotation axis 8) to seat support 4. Rotation of this connection may belocked by any means—an example rotation lock 9. The rear part of theseat mount 2 is rotationally connected (rotation axis 40) to string 41which on its other end is rotationally connected (rotation axis 42) tosliding component 43. Sliding element 43 is connected to seat support 4by means of any sliding mechanism 44. Sliding element 43 is rotationallyconnected (rotation axis 45) to the chair backrest support 5. Rotationalmovement of this connection may be locked by any means—an examplerotation lock 46. Backrest support 20 is affixed to backrest 3. If theseat is dividable the knee support 6 constitutes an extension of theseat when the chair is arranged in the sitting position; if the seat isnot dividable the knee support 6 is placed under the seat and is movedto the kneeling position during conversion of the chair by means of anymechanism.

The embodiment presented on FIGS. 15 and 16 shows the bi-functionalchair for sitting and kneeling equipped with a seat with a changeableangle of inclination, backrest and movable knee support in twopositions. Setting of the backrest angle, seat depth and height of thebackrest over the seat is an automatic process effected duringconversion of the chair from the classic sitting position into thekneeling position and vice versa. Seat mount 2 is rotationally connected(rotation axis 8) to seat support 4. Rotation of this connection may belocked by any means—an example rotation lock 9. The rear part of theseat mount 2 is rotationally connected (rotation axis 46) to string 47which on its other end is rotationally connected (rotation axis 48) tobackrest support mounting plate 49. Backrest support mounting plate 49is rotationally connected to strings 51 and 52, axes 50 and 53, which ontheir other ends are rotationally connected with seat support 4, axes 54and 55. The ends of rotation axes 50, 53, 54 and 55 are arranged inrelation to each other in the form of a rhomboid. Backrest support 5,affixed to backrest 3, is rotationally connected (rotation axis 56) tobackrest support mounting plate 49. The rotation is locked by anymeans—example rotation lock 57. If the seat is dividable the kneesupport 6 constitutes an extension of the seat when the chair isarranged in the sitting position; if the seat is not dividable the kneesupport 6 is placed under the seat and is moved to the kneeling positionduring conversion of the chair by means of any mechanism.

The embodiment presented on FIGS. 17 and 18 shows the bi-functionalchair for sitting and kneeling equipped with a seat with a changeableangle of inclination, backrest and movable knee support in twopositions. Setting of the backrest angle, seat depth and height of thebackrest over the seat is an automatic process effected duringconversion of the chair from the classic sitting position into thekneeling position and vice versa. Seat mount 2 is rotationally connectedto seat support 4—connection rotation axis 8. Rotation may be locked byany means. String 29 is rotationally connected to seat mount2—connection rotation axis 28. On its other end string 29 isrotationally connected to backrest support mounting plate 31—connectionrotation axis 30. String 33 is rotationally connected to the front ofbackrest support mounting plate 31—connection rotation axis 32. On itsother end string 33 is rotationally connected to seat support4—connection rotation axis 34. In addition, string 33 is rotationallyconnected (rotation axis 35) to string 36. On its other end string 36 isrotationally connected to seat mount 2—connection rotation axis 37. Thechair is equipped with a mechanism which during backwards inclination ofbackrest support 5 in the classic sitting position causes automaticinclination of seat 1 along with the mechanism and kneeler around axis8. This mechanism is constructed in such a manner that the backrestsupport mounting plate 31 is rotationally connected to inclination lever58—connection rotation axis 32. One end of the inclination lever 58 issupported on spring 61 a and the other end, which may be equipped withrotating wheel 59, is supported on pusher 60. Inclination lever 58 isaffixed to backrest support 5. Backrest 3 is affixed to backrest support5. If the seat is dividable the knee support 6 constitutes an extensionof the seat when the chair is arranged in the sitting position; if theseat is not dividable the knee support 6 is placed under the seat and ismoved to the kneeling position during conversion of the chair by meansof any mechanism.

The embodiment presented on FIGS. 19 and 20 shows an example utilizationof the bi-functional chair for sitting and kneeling on a stationarypedestal in a configuration which may be used in lecture halls or inmeans of transportation such as buses, trains, ferries or planes.

The embodiment presented on FIGS. 21 and 22 shows the device maintainingthe backrest angle selected by the user without the necessity to lockthe movement of the backrest. It is constructed in such a manner thatthe chair pedestal 62 is connected through a taper joint to chair column63 on which seat support 4 is set. Seat mount 4 is rotationallyconnected (rotation axis 64) to seat mount 2, which in turn is connectedto seat 1. Arm 67 is rotationally connected (rotation axis 66) to seatsupport 4. Arm 67 is also connected to backrest inclination mechanismmount 69 by means of backrest frame rotation axis 68. Backrestinclination mechanism mount 69 is rotationally connected (rotation axis70) to string 71 rotationally connected (rotation axis 72) to the seatmount. Retaining walls 73 and 74 of spring 75 tightened by means ofscrew 76 through washer 77 are affixed to the backrest inclinationmechanism mount 69. Backrest frame rotation axis 68 is joined withspring pusher 78 which pushes bolt 79 connected to washer 80 and passingthrough wall 73. Seat mount 4 is affixed to seat support bracket 81which possesses an aperture through which bolt 82 slides when moved bymeans of lever 83. The bolt enters the aperture in seat support 84connected to the seat mount 2 and blocks the movement of the seat in theclassic or kneeling position.

The embodiment presented on FIG. 23 shows the device maintaining thebackrest angle selected by the user without the necessity to lock themovement of the backrest, which contains an assembly for equalizing theresistance of the backrest with the weight of the user. It isconstructed in such a manner that the chair pedestal 62 is connectedthrough a taper joint to chair column 63 on which seat support 4 is set.Seat support 4 is rotationally connected (rotation axis 64) to seatmount 2, which in turn is rotationally connected (rotation axis 65) toseat 1. Arm 67 is rotationally connected (rotation axis 66) to seatsupport 4. Arm 67 is also connected to backrest inclination mechanismmount 69 by means of backrest frame rotation axis 68. Backrestinclination mechanism mount 69 is rotationally connected (rotation axis70) to string 71 rotationally connected (rotation axis 72) to the seatmount. Retaining walls 73 and 74 of spring 75 tightened by means ofscrew 76 through washer 77 are affixed to the backrest inclinationmechanism mount 69. Backrest frame rotation axis 68 is joined withspring pusher 78 which pushes bolt 79 connected to washer 80 and passingthrough wall 73. Seat mount 4 is affixed to seat support bracket 81which possesses an aperture through which bolt 82 slides when moved bymeans of lever 83. The bolt enters the aperture in seat support 84connected to the seat mount 2 and blocks the movement of the seat in theclassic or kneeling position. The assembly for equalizing the resistanceof the backrest with the weight of the user is constructed in such amanner that the backrest rotation axis 68 is joined with lever 86rotationally connected to slider 87, which in turn is rotationallyconnected to lever 88 rotationally set on axis 89. This axis is set inthe backrest inclination mechanism mount 69. Lever 88 is rotationallyconnected to string 90 which is also rotationally connected to lever 91.Lever 91 is rotationally connected to seat mount 2 by means of axis 92.Lever 91 is rotationally connected to arm 93 which in turn isrotationally connected to seat 1.

1. Bi-functional chair for sitting and kneeling comprising a seat withadjustable angle of inclination, backrest and movable knee supportcharacterized in that it is equipped with devices allowing to change thedistance between the front edge of the seat and the backrest, the angleof inclination of the backrest in relation to the seat and the height ofthe backrest in relation to the seat, which enables conversion of theseat and backrest for classic sitting into a seat and backrest forkneeling and vice versa.
 2. (canceled)
 3. Bi-functional chair forsitting and kneeling equipped with a seat with adjustable angle ofinclination, backrest and movable knee support pursuant to claim 1,characterized in that it is equipped with a device maintaining thebackrest angle selected by the user without the necessity to lock themovement of the backrest manually.
 4. Bi-functional chair pursuant toclaim 3 characterized in that the device maintaining the backrest angleselected by the user without the necessity to lock the movement of thebackrest is constructed in such a manner that the chair pedestal (62) isconnected with the chair column (63) affixed with seat support (4); theseat support (4) is rotationally connected through rotation axis (64) tothe seat mount (2), which is connected to seat (1); the seat support (4)is rotationally connected through rotation axis (66) to arm (67), whichis in turn, through backrest frame rotation axis (68), is connected tothe backrest inclination mechanism mount (69); the backrest inclinationmechanism mount (69) is rotationally connected through rotation axis(70) to string (71) connected rotationally through rotation axis (72) tothe seat mount; the backrest inclination mechanism mount (69) is affixedwith retaining walls (73) and (74) of spring (75) tightened by means ofscrew (76) through washer (77); the backrest frame rotation axis (68) isjoined with spring pusher (78) pushing bolt (79) moving through anaperture in wall (73) and connected to washer (80); the seat support (4)is affixed with seat support bracket (81) with an aperture through whichslides bolt (82) moved by lever (83); the bolt enters the aperture ofthe seat support (84) connected to seat mount (2).
 5. Bi-functionalchair pursuant to claim 3 characterized in that the device maintainingthe backrest angle selected by the user without the necessity to lockthe movement of the backrest comprises an assembly for equalizing theresistance of the backrest with the weight of the user and isconstructed in such a manner that the chair pedestal (62) is connectedwith the chair column (63) affixed with seat support (4); the seatsupport (4) is rotationally connected through rotation axis (64) to theseat mount (2), which is connected to seat (1) through rotation axis(65); the seat support (4) is rotationally connected through rotationaxis (66) to arm (67), which is in turn, through backrest frame rotationaxis (68), is connected to the backrest inclination mechanism mount(69); the backrest inclination mechanism mount (69) is rotationallyconnected through rotation axis (70) to string (71) connectedrotationally through rotation axis (72) to the seat mount; the backrestinclination mechanism mount (69) is affixed with retaining walls (73)and (74) of spring (75) tightened by means of screw (76) through washer(77); the backrest frame rotation axis (68) is joined with spring pusher(78) pushing bolt (79) moving through an aperture in wall (73) andconnected to washer (80); the seat support (4) is affixed with seatsupport bracket (81) with an aperture through which slides bolt (82)moved by lever (83); the bolt enters the aperture of the seat support(84) connected to seat mount (2); the backrest rotation axis (68) isjoined with lever (86) rotationally connected to slider (87), which inturn is rotationally connected to lever (88) rotationally set on axis(89) mounted on the backrest inclination mechanism mount (69); lever(88) is rotationally connected to string (90) which is rotationallyconnected to lever (91), which in turn is rotationally connected throughaxis (92) to the seat mount (2); lever (91) is rotationally connectedwith arm (93) which is rotationally connected to seat (1). 6.Bi-functional chair for sitting and kneeling comprising a seat withchangeable angle of inclination, backrest and movable knee supportpursuant to claim 1 characterized in that the seat (1) is slideconnected by means of any type of sliding mechanism (7) equipped withslide lock, to the seat mount (2); seat mount (2) is rotationallyconnected, with any type of rotation lock, to chair pedestal assembly(4)—connection rotation axis (8); seat mount (2) is rotationallyconnected, with any type of rotation lock, to backrest support(5)—connection rotation axis (10); backrest support (5) is connected tobackrest (3) by means of any type of sliding mechanism (14) locked inany manner, which allows for vertical sliding; if the seat is dividableknee support (6) constitutes an extension of the seat when the chair isarranged in the sitting position; if the seat is not dividable the kneesupport (6) is placed under the seat and is moved to the kneelingposition during conversion of the chair by means of any type ofmechanism.
 7. Bi-functional chair for sitting and kneeling comprising aseat with changeable angle of inclination, backrest and movable kneesupport pursuant to claim 1 characterized in that seat mount (2) isrotationally connected, through any type of rotation lock, to the chairpedestal assembly (4)—connection rotation axis (8); seat mount (2) isconnected by means of any type of rotating and sliding mechanism (15)with any type of movement lock, to backrest support (5)—connectionrotation axis (16); backrest support (5) is connected by means of anytype of sliding mechanism allowing for vertical movement (14), with anytype of slide lock, to backrest (3); if the seat is dividable kneesupport (6) constitutes an extension of the seat when the chair isarranged in the sitting position; if the seat is not dividable kneesupport (6) is placed below the seat and is moved to the kneelingposition during conversion of the chair by means of any type ofmechanism.
 8. Bi-functional chair for sitting and kneeling comprising aseat with changeable angle of inclination, backrest and movable kneesupport pursuant to claim 1 characterized in that seat mount (2) isrotationally connected, through any type of rotation lock, to the chairpedestal assembly (4)—connection rotation axis (8); the end of seatmount (2) is rotationally connected to backrest support (5)—connectionrotation axis (18); backrest support (5) is shaped in such a manner thatin the sitting position the lumbar support point of the backrest locatedclosest to the front overlaps at least 35 mm on the seat; backrestsupport (5) is connected to backrest (3); if the seat is dividable kneesupport (6) constitutes an extension of the seat when the chair isarranged in the sitting position; if the seat is not dividable kneesupport (6) is placed below the seat and is moved to the kneelingposition during conversion of the chair by means of any type ofmechanism.
 9. Bi-functional chair for sitting and kneeling comprising aseat with changeable angle of inclination, backrest and movable kneesupport pursuant to claim 1 characterized in that seat mount (2) isrotationally connected, through any type of rotation lock, to the chairpedestal assembly (4)—connection rotation axis (8); the end of seatmount (2) is rotationally connected to backrest support (5)—connectionrotation axis (18); backrest support (5) is shaped in such a manner thatin the sitting position the lumbar support point of the backrest locatedclosest to the front overlaps at least 35 mm on the seat; backrestsupport (5) is connected to backrest (3); the chair comprises amechanism automatically adjusting the angle between the backrest and theseat during conversion of the chair from the classic sitting position tothe kneeling position, constructed in such a manner that the chairpedestal assembly (4) is rotationally connected to string(21)—connection rotation axis (22); the other end of the string (21) isrotationally connected to sliding component (24)—connection rotationaxis (23); sliding component (24) is slide connected to seat mount (2)in a manner allowing for horizontal movement from the front to the endof the seat and vice versa; sliding component (24) is rotationallyconnected to string (25)—connection rotation axis (23); the other end ofstring (25) is rotationally connected to the short arm of backrestsupport (27)—connection rotation axis (26). If the seat is dividable theknee support (6) constitutes an extension of the seat when the chair isarranged in the sitting position; if the seat is not dividable the kneesupport (6) is placed under the seat and is moved to the kneelingposition during conversion of the chair by means of any mechanism. 10.Bi-functional chair for sitting and kneeling comprising a seat withchangeable angle of inclination, backrest and movable knee supportpursuant to claim 1 characterized in that seat mount (2) is rotationallyconnected, through any type of rotation lock, to the chair pedestalassembly (4)—connection rotation axis (8); seat mount (2) isrotationally connected to string (29)—connection rotation axis (28); theother end of string (29) is rotationally connected to backrest supportmounting plate (31)—connection rotation axis (30); the front of backrestsupport mounting plate (31) is rotationally connected to string(33)—connection rotation axis (32); the other end of string (33) isrotationally connected to chair pedestal assembly (4)—connectionrotation axis (34); string (33) is additionally rotationally connectedto string (36)—connection rotation axis (35); the other end of string(36) is rotationally connected to seat mount (2)—connection rotationaxis (37); backrest support mounting plate (31) is rotationallyconnected, with any type of rotation lock, to backrest support(5)—connection rotation axis (38); backrest support (5) is affixed tobackrest (3); if the seat is dividable knee support (6) constitutes anextension of the seat when the chair is arranged in the sittingposition; if the seat is not dividable knee support (6) is placed belowthe seat and is moved to the kneeling position during conversion of thechair by means of any type of mechanism.
 11. Bi-functional chair forsitting and kneeling comprising a seat with changeable angle ofinclination, backrest and movable knee support pursuant to claim 1characterized in that seat mount (2) is rotationally connected, throughany type of rotation lock, to the chair pedestal assembly (4)—connectionrotation axis (8); the rear of the seat mount (2) is rotationallyconnected to string (41)—connection rotation axis (40); the other end ofstring (41) is rotationally connected to sliding component(43)—connection rotation axis (42); sliding component (43) is slideconnected by means of any type of sliding mechanism (44) to chairpedestal assembly (4); sliding component (43) is rotationally connected,with any type of rotation lock, to backrest support (5)—connectionrotation axis (45); backrest support (5) is affixed to backrest (3); ifthe seat is dividable knee support (6) constitutes an extension of theseat when the chair is arranged in the sitting position; if the seat isnot dividable knee support (6) is placed below the seat and is moved tothe kneeling position during conversion of the chair by means of anytype of mechanism.
 12. Bi-functional chair for sitting and kneelingcomprising a seat with changeable angle of inclination, backrest andmovable knee support pursuant to claim 1 characterized in that seatmount (2) is rotationally connected, through any type of rotation lock,to the chair pedestal assembly (4)—connection rotation axis (8); seatmount (2) is rotationally connected to string (47)—connection rotationaxis (46), the other end of string (47) is rotationally connected tobackrest support mounting plate (49)—connection rotation axis (48);backrest support plate (49) is rotationally connected to strings (51)and (52)—connection rotation axes (50) and (53); the other ends ofstrings (51) and (52) are rotationally connected to chair pedestalassembly (4)—rotation axes (54) and (55); the ends of rotation axes(50), (53), (54) and (55) are arranged in relation to each other in theform of a rhomboid; backrest support mounting plate (49) is rotationallyconnected, with any type of rotation lock, to backrest support(5)—connection rotation axis (56); backrest support (5) is connected tobackrest (3); if the seat is dividable knee support (6) constitutes anextension of the seat when the chair is arranged in the sittingposition; if the seat is not dividable knee support (6) is placed belowthe seat and is moved to the kneeling position during conversion of thechair by means of any type of mechanism.
 13. Bi-functional chair forsitting and kneeling comprising a seat with changeable angle ofinclination, backrest and movable knee support pursuant to claim 1characterized in that seat mount (2) is rotationally connected, throughany type of rotation lock, to the chair pedestal assembly (4)—connectionrotation axis (8); seat mount (2) is rotationally connected to string(29)—connection rotation axis (28); the other end of string (29) isrotationally connected to backrest support mounting plate(31)—connection rotation axis (30); the front of backrest supportmounting plate (31) is rotationally connected to string (33)—connectionrotation axis (32); the other end of string (33) is rotationallyconnected to chair pedestal assembly (4)—connection rotation axis (34);string (33) is additionally rotationally connected to string(36)—connection rotation axis (35); the other end of string (36) isrotationally connected to seat mount (2)—connection rotation axis (37);the chair comprises a mechanism which in the classic sitting position,during backwards inclination of the backrest support (5) causesbackwards inclination of the seat (1) along with the mechanism and theknee support around axis (8); the mechanism is constructed in such amanner that the backrest support mounting plate (31) is rotationallyconnected to inclination lever (58)—connection rotation axis (32); oneend of the inclination lever (58) leans on string (61) and the otherend, which may be equipped with a rotating wheel (59), leans on pusher(60); inclination lever (58) is affixed to backrest support (5).Backrest (3) is affixed to backrest support (5); if the seat isdividable the knee support (6) constitutes an extension of the seat whenthe chair is arranged in the sitting position; if the seat is notdividable the knee support (6) is placed under the seat and is moved tothe kneeling position during conversion of the chair by means of anymechanism.